A new study suggests that the gravitational waves detected by the LIGO experiment must have come from black holes generated during the collapse of stars, and not in the earliest phases of the Universe.

This study implies that it's not at all probable that black holes with masses between 10 and 100 times the mass of the Sun make up a significant fraction of the dark matter.

“This is a very nice candidate for a recoiling supermassive black hole,” says Francesca Civano of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. Recoiling black holes are created when two monster black holes from different galaxies merge, says Civano, who was not involved in the new study. If the black holes have different masses and rotate at different rates, the collision can generate gravitational waves more strongly in one direction, booting the newly merged black hole the other way.

A radiation-gushing supermassive black hole called quasar 3C 186 and its host galaxy, about 8 billion light-years from Earth in the constellation Lynx, tipped off Chiaberge and colleagues to the recoiling black hole. The team noticed that the quasar wasn’t at the center of the galaxy, where it typically should be. “We knew this was clearly weird. It was clearly different than all of the other quasars and galaxies we were seeing,” Chiaberge says.